Zhang Qi, Gui Keting
School of Energy and Environment, Southeast University, Nanjing 210008, PR China.
J Hazard Mater. 2009 Sep 15;168(2-3):1341-5. doi: 10.1016/j.jhazmat.2009.03.019. Epub 2009 Mar 18.
The magnetically fluidized bed (MFB) was used as the reactor in a novel semidry flue gas desulfurization (FGD) process to achieve high desulfurization efficiency. Experiments in a laboratory-scale apparatus were conducted to reveal the effects of approach to adiabatic saturation temperature, Ca/S molar ratio and applied magnetic field intensity on SO(2) removal. Results showed that SO(2) removal efficiency can be obviously enhanced by decreasing approach to adiabatic saturation temperature, increasing Ca/S molar ratio, or increasing applied magnetic field intensity. At a magnetic field intensity of 300Oe and a Ca/S molar ratio of 1.0, the desulfurization efficiency (excluding desulfurization efficiency in the fabric filter) was over 80%, while spent sorbent appeared in the form of dry powder. With the SEM, XRD and EDX research, it can be found that the increase of DC magnetic field intensity can make the surface morphology on the surface of the ferromagnetic particles loose and enhance the oxidation of S(IV), hence reducing the liquid phase mass transfer resistance of the slurry droplets and increasing desulfurization reaction rate, respectively. Therefore, the desulfurization efficiency increased obviously with the increase of DC field intensity.
磁流化床(MFB)被用作一种新型半干法烟气脱硫(FGD)工艺中的反应器,以实现高脱硫效率。在实验室规模的装置中进行了实验,以揭示接近绝热饱和温度、钙硫摩尔比和外加磁场强度对SO₂脱除的影响。结果表明,通过降低接近绝热饱和温度、提高钙硫摩尔比或增加外加磁场强度,可以显著提高SO₂脱除效率。在磁场强度为300Oe且钙硫摩尔比为1.0时,脱硫效率(不包括布袋除尘器中的脱硫效率)超过80%,而废吸附剂呈干粉形式。通过扫描电子显微镜(SEM)、X射线衍射(XRD)和能谱分析(EDX)研究发现,直流磁场强度的增加可使铁磁性颗粒表面的形貌变得疏松,并增强S(IV)的氧化,从而分别降低浆液滴的液相传质阻力并提高脱硫反应速率。因此,脱硫效率随直流磁场强度的增加而明显提高。